Companion animals such as dogs and cats frequently require differing diets depending on their life stage (age), size, body composition, and breed. Both dog and cat nutrient requirements can be separated into three different life-stages, based on age: growing dogs (or cats), adult dogs (or cats), and senior dogs (or cats). The latter category, senior dogs (or cats), can be further separated into two stages, which include senior (or mature adult) and super senior (or geriatric). Dogs are further separated into different categories for regular breed dogs versus large-breed dogs.
Essential fatty acids, consisting of omega-3 and omega-6 polyunsaturated fatty acids, are critical nutrients for the health of an animal. These nutrients, however, either cannot be made by animals or cannot be made in sufficient amounts to elicit benefits and therefore must be consumed in an animal's diet. See, e.g., Hornstra, G., et al., “Essential fatty acids in pregnancy and early human development”, Eur. J. Obs. & Gyn. and Reprod. Biology, 61:57-62 (1995). It has previously been postulated that Docosahexaenoic Acid (“DHA”), an omega-3 polyunsaturated fatty acid, is effective in increasing the maze-learning ability and brain functions in aged mice. See, Lim, S.-Y., “Intakes of dietary docosahexaenoic acid ethyl ester and egg phosphatidylcholine improve maze-learning ability in young and old mice”, J. Nutr., 130:1629-1632 (2000).
Rogers discusses the theory of the potential use of antioxidants to slow the deterioration of cognitive function, particularly in the elderly. See Rogers, P., “A healthy body, a healthy mind: long-term impact of diet on mood and cognitive function”, Proceedings of the Nutrition Society, 60:135-143 (2001).
Despite the studies and developments relating to improving cognitive abilities, there continues to be a need for methods for enhancing the quality of life of senior animals, as measured by, e.g., enhanced alertness, improved vitality, cartilage protection, maintenance of muscle mass, enhanced digestibility, and improved skin and pelage quality in senior and super senior animals. As previously reported, the super senior pet food composition described herein may be administered to achieve this result. Additionally, we now report herein our surprising discovery that the enhanced quality of life of senior and super senior animals achieved by the administration of the pet food compositions disclosed herein is reflected at the genomic level. Specifically, as described in detail in the Examples below, gene chip data indicate that the expression of genes that encode proteins associated with several biological pathways such as blood clotting and platelet activation and aggregation, bone and muscle integrity, inflammatory responses, cartilage degradation and pain response, DNA damage and repair pathways, neural function, glycogen synthesis and degradation, glycolysis, gluconeogenesis, the pentose phosphate pathway and electron transport are modified, i.e., in general, the majority are beneficially altered through administration to the animal of the super senior pet food compositions described herein.